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 M3//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20220429T152410Z
DTSTART:20220504T140000Z
DTEND:20220504T150000Z
SUMMARY:Logic Seminar - Rosario Mennuni (Pisa)
UID:{http://www.columbasystems.com/customers/uom/gpp/eventid/}l1kc-l27q20
 xg-guj75d
DESCRIPTION:Title: Automorphisms of ordered abelian groups and positive l
 ogic\n\nAbstract: A common construction in model theory consists in star
 ting with a theory T\, adding to the language a symbol for an automorphi
 sm\, resulting in a theory T'\, and looking at the class K of existentia
 lly closed models of T'. Sometimes\, the class K is elementary\; this is
  for example true when T is the theory of algebraically closed fields\, 
 where the corresponding theory of K is known as ACFA.\n\nOn the other ha
 nd\, when T is a theory with SOP\, by a result of Kikyo and Shelah the c
 lass K is not elementary. Nevertheless\, positive logic allows to apply 
 model theoretic techniques to the study of this class. In ongoing work o
 f Jan Dobrowolski and myself\, we look at the behaviour of NIP in this s
 etting. For example\, if T is the theory of dense linear orders\, then t
 he positive theory of K is NIP. We then look at the case where T is the 
 theory of (divisible) ordered abelian groups.\n\nIn this talk\, I will g
 ive a brief introduction to positive logic\, review some existing result
 s about generic automorphisms of ordered structures\, and then report on
  ongoing work of Jan and myself about the class of divisible ordered abe
 lian groups with an automorphism.
STATUS:TENTATIVE
TRANSP:TRANSPARENT
CLASS:PUBLIC
LOCATION:Frank Adams 1 (and zoom\, link in email)\, Alan Turing Building\
 , Manchester
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